This invention relates to a shaft angle sensor suitable for use in an automotive environment, and more particularly, to a shaft angle sensor employing magneto-resistive material for reduced sensitivity to spacing between rotary and stationary elements of the sensor.
In the use of electrical and electromechanical systems in an automobile, it is often necessary to employ an angle sensor to provide an indication of an angle of rotation of a rotatable component relative to a fixed component in the automobile. By way of examples, electrical circuitry is employed: (1) in the operation of a throttle body and/or carburetor with respect to the positioning of a butterfly valve, (2) in conjunction with the positioning of a throttle pedal for feeding fuel to an engine, (3) in conjunction with measurement of rotational angle of shaft used in rotary chassis height sensor equipment, (4) in an electronic throttle body sensor for regulating fuel to an engine, as well as in (5) operation of brake, clutch and positioning of a gear selection, by way of example. It is desirable to have such sensing of rotational angle to be accomplished precisely for optimum operation of the foregoing components of the automobile. However, the automobile represents a hostile environment to the employment of such sensors because of vibration, dirt, and temperature variations, as well as to mechanical concerns of tolerance, spacing, displacement, shaft and bearing wear. A further difficulty arises in the fabrication of the sensor for the automotive environment wherein there is need for excessive precision in the assembly of the sensor.